DESCRIPTION (investigator's abstract): Over the last decade there has been increased recognition that a subset of obese patients report binge eating episodes similar to those seen in patients with bulimia nervosa. However, individuals with binge eating disorder (BED) do not engage in compensatory behavior and therefore tend to become obese. These individuals with BED have the increased health risk associated with obesity, are at increased risk of developing psychiatric disorders, and have high rates of treatment failure making this an important disorder to study. While certain aspects of the eating behavior of individuals with BED have been studied, important questions about energy intake patterns, nutrient composition and food selection remain unanswered. Additionally, some of the best methods that are available for the study of human energy intake have not yet been applied to this population. We propose to use a comparison of results from several methods to develop a detailed understanding of total energy intake, meal patterning, and nutrient and food selection in obese individuals with BED compared to body mass index (BMI, kg/m2) matched individuals with no history of binge eating. The specific aims of this study are to determine: (1) whether individuals with BED have a higher daily energy intake on average than their non-BED counterparts, (2) how the patterns of energy intake, food selection and nutrient composition differ between individuals with and without a BED diagnosis during meals and overeating episodes, determine the nature of binge eating episodes in the BED population. We hypothesize that: (1) there will be a significant elevation in the total energy intake per day in individuals with BED compared to non-BED individuals; (2) patterns of energy intake will be significantly different between the two groups and; (3) nutrient selection and food selections will differ between individuals with BED and individuals who do not have current or past binge eating episodes. We propose to add to the current body of knowledge in this area with the use of the doubly labeled water (DLW) technique to validate the accuracy of self-reported energy intake records. This study will provide the first direct evidence of the relationship between energy expenditure and self-reported energy intake in individuals with BED. We propose the use of random 24-hour dietary recall interviews to collect dietary intake data in individuals with and without a BED diagnosis. This method has not previously been applied to the study of this disorder. We propose to compare energy intake data collected during binge eating episodes and normal meals in a laboratory setting with comparable data collected during the random dietary recall interviews and the DLW study. A thorough understanding of the energy intake patterns in BED and non-BED individuals will lead to a better understanding of the descriptive nature of the disorder. It will also help to guide treatment priorities and aid researchers in prioritizing which biological systems to study gain insight into the underlying pathophysiology of this disorder.